Acquisitions (Details) - USD ($) $ in Thousands		3 Months Ended
	Dec. 31, 2020	Jul. 31, 2021	Jul. 31, 2020	Apr. 30, 2021	[1]
Acquisitions [Abstract]
Fair value of cash consideration transferred, including those amounts paid after acquisition, net of cash acquired		$ 3,032	$ 136
Revenue		488,388	431,326
Operating income		40,968	$ 30,039
Goodwill		1,301,599		$ 1,304,340
Research Publishing & Platforms [Member]
Acquisitions [Abstract]
Goodwill		618,440		$ 619,203
Hindawi [Member]
Acquisitions [Abstract]
Percentage of ownership interest acquired	100.00%
Fair value of consideration transferred	$ 300,100
Total cash consideration transferred	299,300
Settlement of preexisting relationship	800
Cash acquired	1,000
Fair value of cash consideration transferred, including those amounts paid after acquisition, net of cash acquired	298,300
Intangible assets, net	194,900
Hindawi [Member] | Research Publishing & Platforms [Member]
Acquisitions [Abstract]
Revenue		11,500
Operating income		$ 1,800
Goodwill	$ 147,400

[1] The Education Services goodwill balance as of April 30, 2021 includes a cumulative pretax noncash goodwill impairment of $110.0 million.